Sumner residences below Richmond Hill experienced significant flood damage during the October 2000 storm with flooding of 12 houses and commercial premises. Further housing on Richmond Hill will generate more stormwater runoff. Improvements are needed to both reduce the existing flood risk to this part of Sumner and bring it to a standard similar to the rest of Christchurch and to manage stormwater from the Richmond Hill subdivision.
What improvements have already been made?
The Richmond Hill waterway was widened above Nayland St, the Nayland St inlet structure to the Cave Rock pipeline was enlarged, the operation of the flap-gate outlet to the pipeline at Cave Rock was improved, and City Care’s flood emergency procedures were reviewed and upgraded after the October 2000 flooding. Despite these major improvements, a risk of flood damage in Sumner still remains because the capacity of the Cave Rock pipeline would not cope with a more extreme flood.
A secondary flow path to convey flood overflows from the Nayland St inlet structure to Sumner Beach. The secondary flow path will be along the walkway from Richmond Hill then will be piped under Marriner St and the Esplanade and discharge at the back of the beach by the Surf Club building. (this was copied out of the chch city council website)
Sumner flood
Sumner residences below Richmond Hill experienced significant flood damage during the October 2000 storm with flooding of 12 houses and commercial premises. Further housing on Richmond Hill will generate more stormwater runoff. Improvements are needed to both reduce the existing flood risk to this part of Sumner and bring it to a standard similar to the rest of Christchurch and to manage stormwater from the Richmond Hill subdivision.
What improvements have already been made?
The Richmond Hill waterway was widened above Nayland St, the Nayland St inlet structure to the Cave Rock pipeline was enlarged, the operation of the flap-gate outlet to the pipeline at Cave Rock was improved, and City Care’s flood emergency procedures were reviewed and upgraded after the October 2000 flooding. Despite these major improvements, a risk of flood damage in Sumner still remains because the capacity of the Cave Rock pipeline would not cope with a more extreme flood.
A secondary flow path to convey flood overflows from the Nayland St inlet structure to Sumner Beach. The secondary flow path will be along the walkway from Richmond Hill then will be piped under Marriner St and the Esplanade and discharge at the back of the beach by the Surf Club building.
(this was copied out of the chch city council website)